Using equipment intended to save energy is a losing battle if that equipment isn't working properly. A new diagnostic system developed at Pacific Northwest National Laboratory can help ensure economizer devices purchased for rooftop air-conditioning units are working at peak performance.

PNNL's diagnostician allows building managers to remotely monitor conditions like temperature and thermostat control commands. Rather than a technician climbing onto the roof, opening the air-conditioning unit and taking measurements by hand, the rooftop diagnostician records all that information and posts it on a web page, enabling technicians to monitor the system from a desk. The constant collection of data also provides a more comprehensive view of the system's performance.

Future enhancements will include capabilities to check efficiency levels and the condition of filters and coils. The diagnostician also could be useful in monitoring chillers, boilers and substations.